Indigo dyeing of polyester fibers

ABSTRACT

Polyester fiber can be dyed with indigo so as to possess washdown and fading characteristics similar to indigo-dyed cotton fibers provided they are first coated with a polymeric salt having the following repeating units: ##STR1## with from 0 to 75 mol % of another ethylenically unsaturated monomeric unit, 
     or ##STR2## wherein R is hydrogen, methyl or ethyl 
     R 1  is a divalent hydrocarbon radical of 1 to 4 C atoms 
     R 2  and R 3  are lower alkyl (from 1 to 4 C atoms) 
     R 4  is hydrogen, hydroxyethyl or lower alkyl (from 1 to 4 C atoms) 
     X -  is an anion 
     Preferably, in Formula A, R 1  contains 2 carbon atoms; R 2  ═R 3  ═R 4  ═methyl; and X -  is 83 mol % CH 3  SO 4  -- and 17 mol % C 18  H 35  SO 4  --.



